Google is performing regularly scheduled maintenance on May 16th, 2009. AdSense and Ad Manager accounts will not be accessible though ad targeting and serving won’t be affected. In addition, clicks, impressions, and earnings will be recorded as usual.

Here’s the maintenance start time, converted for a few cities around the world:

London – 6pm Saturday
Dubai – 9pm Saturday
Mumbai – 10:30pm Saturday
Taipei – 1am Sunday
Auckland – 5am Sunday

-NKJ

Source: Google